Controlling device for air conditioning systems



May 28, 1946.

A. c. BOO-TH CONTROLLING DEVICE FOR AIR CONDITIONING SYSTEMS Filed Feb. 14, 1945 2 heets-Sheet l Snow viva Arthur 6.30023 7,

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CONTROLLING DEVICE FOR AIR CONDITIONING SYSTEMS Filed Feb. 14, 1945 2 Sheets-sheet 2 imam tow Ari/tum 6.300112 Moi/MW Patented May 28, 1946 CONTROLLING DEVICE FOR AIR CONDITIONING SYSTEMS Arthur C. Booth, North Ferrisburg, Vt.

Application February 14, 1945, Serial No. 577,854

(Cl. ZOO-52) 1 Claim.

This invention relates to air conditioning systems and more particularly a device for controlling the operation of the same.

One of the objects of this invention resides in the provision of means whereby air conditioning systems can be controlled in accordance with the degree of humidity within that area of a room or building having the system installed therein.

Another object of this invention resides in the provision of means whereby operation of air conditionlng systems can be regulated to meet predetermined temperature conditions within rooms and building provided with such systems.

A further object of this invention resides in the provision of means for controlling the electrical systems of air conditioning systems in accordance with predetermined degrees of humidity within rooms or building provided with air conditioning systems.

A still further object of this invention resides in the provision of means whereby the exact temperature of rooms or building can be main- .tained subsequent to adjusting the means for onoration under the influence of a predetermined degree of humidity with a room or building.

Aside from the aforesaid objects, this invention resides in the provision of means adapted to be operated under the wet and dry bulb thermometer principle in controlling air conditioning systems of rooms and building.

In addition to the foregoing objects, this invention resides in the particular manner of setting the device for controlling air conditioning systems,

With these and other objects in view, this invention resides in certain novel features of construction and arrangement or elements to be hereinafter more particularly set forth in the specification, illustrated in the accompanying drawings and pointed out in the appended claim and, although this disclosure depicts my present conception of the invention, the right is reserved to resort to such changes in construction and arrangement of elements as come within the spirit of the invention.

In the accompanying drawings forming a part of this application;

Fig. 1 is a side view oi. the controlling device.

Fig. 2 is a longitudinal vertical sectional view therethrough.

Fig. 3 is an enlarged vertical sectional view through the neck of the cylinder and connection thereof to the mercury tube.

Fig. 4 is an enlarged sectional view through a portion of the cylinder,

Fig. 5 is a honzontai sectional view through the cylinder taken approximately on line 5-5 of Fig. 2.

Fig. 6 is an enlarged vertical sectional view through the lower portion of the contact plunger. I In the present illustration of this invention, the numeral 5 designates, in general, a device for controlling the operation or air conditioning systems in accordance with predetermined degrees of humidity to be had in rooms and buildings and, in the instant disclosure, the same is mounted on a wall W but may be supported by any suitable element where it may be electrically connected to the electric system of the air conditioning system which it is to control.

The device 5 consists of an elongated cylinder 6 having a neck 1 at its lower end and sealed at its upper end by a removable cap 8 which is provided with an upstanding boss 9 having a bore l 0 therein and a packing gland i I adapted to retain a packing l2 preferably of a graphite base so as to frictionally support an electric contact plunger l3 axially within the cylinder for perpendicuiar movement therein.

Connected to the lower portion of the neck of the cylinder in airtight relation thereto as by a sleeve i4 is a substantially U-shape tube l5 within which is retained a predetermined volume 01' mercury indicated by the numeral iii.

The aforesaid contact plunger i3 extends outwardly beyond the packing gland i I into engagement with a rocker arm I7 having its free end i8 constructed in the form oi! a pointer to operate in conjunction with an adjustable indicating scale I9 attached to the wall W or other suitable place adjacent the pointer,

Engaging the rocker arm i! on that side thereof opposite the side engaged by the aforesaid contact plunger is an expansion thermostat 20 adapted to be actuated by the temperature within a room or building wherein the air conditioning system is installed.

Disposed on the contact plunger and bearing at its inner end against the packing gland is an expansion coil spring 2i and, in order to regulate the force of the thermostat 20 against the contact plunger as by the rocker arm il an adjustable control nut 22 is threadedly disposed on the contact plunger and bears against the outer end of the spring. Through the lnstrumentality of the aforesaid association oi elements it will. be noted that, when said control nut has been changed from a previously set position and the pressure balance along the rocker arm has been disrupted. an immediate change in the controller will prevail. This change being caused by the humidity in the room or building and the contact system will be sensitive to the same when equilibrium has been established by the device.

Secured t and insulated from the contact plunger, at its inner end, is a conductor rod 23 which extends axially into the neck oi the cylinder ior contact with the mercury within the tube II to make electrical connection between a terminal 24 carried by the sleeve and projecting into the mercury and an electrical terminal 26 carried by the cylinder cap and contacting said conductor rod It at all times by a tension arm ll carried thereby. Said electrical terminal 2! is herein disclosed as being in the iorm oi an elongated rod threaded secured and sealed to the cylinder cap to prevent escape oi nitrogen injected into the cylinder through the instrumentality of a valved conduit 21 connected to the cap or any other desired portion oi the cylinder.

Removably threaded into the sleeve II is a niling plug II to permit injection oi the mercury into the tube ll.

Disposed against the outer periphery oi the cylinder 0 is a wick ll adapted to retain moisture at a low temperature irom a cistern or the like. not shown, in order that the nitrogen within the cylinder will remain cool and not expand until the humidity within the room increases.

Extending irom the terminals 24 and 25 are electric wires ill and t! which have their opposite ends connected to the electric power system oi the air conditioning system, not shown. so as to control the same by the controlling device iorming the subject matter oi this application.

With the aioresaid device connected to the electric system oi an air conditioning system the thermostat ll acts as a dry bulb thermometer iorcing the plunger it into proper contact position at varying temperatures. when said plunger is in exact position ior a certain room or building temperature, the nitrogen in the cylinder 8 is retained in inactive condition within the cylinder by the cooling eiiect oi the wick ied by a cistern oi water or other similar means. The evaporating water causes a cooling effect and thereby reduces the temperature oi the nitrogen. when the moisture content in the air is below the set relatlve humidity and under range is experienced between the two thermometer elements causing a reduction in pressure the mercury is permitted to level on until it iorms an equilibrium pressure, or comes in contact with contact rod 23, whereupon. the air conditioning system is started and thus discharges or throws moisture into the surrounding atmosphere. with more moisture per cubic ioot. the relative humidity will be increased until the thermometer diflerential has been sumciently reduced at which point the cooling eilect or evaporation rate has been reduced on the suriace oi the cylinder. With the nitrogen in cylinder 6 at a higher degree in temperature, greater expansion occurs and forces the mercury back into the tube It and away irom the contact 24 thus breaking the circuit between said contact and contact rod 28 and thereby automatically rendering the air conditioning system inoperative until the aioresaid circuit is again closed as aioresaid.

With this invention iully described, it is maniiest that means are provided whereby air conditioning systems can be precision regulated in accordance with predetermined degrees oi humidity and, through the simplicity oi the embodiment set iorth, wear is reduced to the minimum and the cost of manuiacture suiiiciently low to meet public acceptance.

Having thus described my invention what I claim and desire to protect by Letters Patent is:

A device ior controlling the operation oi an air conditioning system operated by electrical power comprising, a cylinder having one end open and a neck iormed on its opposite end, a cap removably sealed on the open end 0! the cylinder, a boss having a bore therein carried by said cap and extending axially therefrom, a contact plunger slidably extending through the bore oi said boss. a packing gland in the boss and surrounding the contact plunger, an expansion coil spring surrounding the contact plunger and resting on the packing gland, an adjustable nut on the contact plunger and engaging the outer end oi said spring, a rocker arm engaging the tree outer end oi the contact plunger and having its iree end formed into a pointer, an adjustable scale disposed adjacent the pointer end of the rock arm, a thermostat engaging the rocker arm adjacent the free end thereoi, a substantially U-shape tube containing mercury, a sleeve connecting and sealing one end of the tube to the outer end oi the neck of the cylinder, a contact secured to the sleeve and extending therein, a contact rod dielectrically connected to the inner end oi the contact plunger and extending therefrom toward the mercury within the tube, a conductor rod secured to. the cap and extending within the cylinder, a contact arm carried by said conductor rod and yieldingly bearing against the aforesaid contact rod carried by the contact plunger, a filling plug in the sleeve tor the mercury, a illiing conduit including a valve in the cap for injecting nitrogen into the cylinder, and a moisture retaining wick surrounding the cylinder to cool the nitrogen within the same.

ARTHUR C. BOOTH. 

